1. Field of the Invention
The invention relates to a new polyaniline-added prepolymer and a method of manufacturing the polyaniline-added prepolymer. In addition, the invention relates to a polyaniline graft polymer that is obtained by addition-polymerizing the polyaniline-added prepolymers and a method of manufacturing the polyaniline graft polymer. In addition, the invention relates to a three-dimensional cross-linked material of a polyaniline graft polymer. Furthermore, the invention relates to a paint that contains the polyaniline graft polymer or the three-dimensional cross-linked material of the polyaniline graft polymer as a coating component.
2. Description of the Related Art
Polyaniline (PANI) is also called aniline black, and is a black powdery polymeric substance that is obtained in such a manner that aniline undergoes oxidative chemical polymerization or electrochemical polymerization. Polyaniline is a conductive polymer, so, in recent years, application of polyaniline to wide fields, such as an electrode material of a battery, an antistatic material, an electromagnetic wave shielding material, a photoelectron conversion device, an optical memory, functional devices of various sensors, or the like, a display device, various hybrid materials, a transparent conductor and various terminal equipments, has been studied as a new electronic material or conductive material.
However, generally, polyaniline has a highly developed p-conjugated system. The polymer principal chain is rigid, and the interaction between molecular chains is strong. In addition, a large number of strong hydrogen bonds are present between the molecular chains, so polyaniline is insoluble in almost all organic solvents. In addition, polyaniline does not melt even when it is heated, so it has poor formability and it is difficult to be made as a film, or the like. Therefore, according to a related art, monomers are impregnated into a base material, such as a fiber or porous body of a polymeric material having a desired shape, and then the monomers are brought into contact with an adequate polymerization catalyst to be polymerized by electrolytic oxidation or monomers are polymerized in the presence of thermoplastic polymer powder to obtain an electroconductive composite.
J. Chem. Soc., Chem. Commun., 1989, 1736 describes a polyaniline that is synthesized by selecting a polymerization catalyst and a reaction, temperature and is soluble in N-methyl-2-pyrrolidone. However, this polyaniline is also almost insoluble in other general organic solvents, and the adaptive range of the polyaniline is limited. In addition, various aniline derivatives are used to synthesize polyaniline derivatives that are soluble in an organic solvent; however, a film having a sufficient flexibility has not yet been made. Furthermore, introduction of substituents, such as alkyl chain, has also been studied; however, this causes a decrease in heat resistance of polyaniline into which these substituents are introduced.
Japanese Patent Application Publication No. 6-100691 (JP-A-6-100691) describes a polyaniline derivative having a graft structure. Polyaniline is caused to react with polysiloxane that has a group reacting with an amino group at a terminal. Thus, the polyaniline derivative is able to dissolve or swell in an organic solvent and is able to form a flexible self-supported film or fiber having high heat resistance. However, this polyaniline derivative is formed so that any one of or both of a quinodiimine structural unit and an imino-1,4-phenylene structural unit is randomly combined with an N-polysiloxane graft-imino-1,4-phenylene structural unit. Therefore, a method of manufacturing the polyaniline is complicated, and, in addition, the polyaniline does not have a solvent dispersibility and long-term dispersion stability that are necessary when used for paint, or the like.
On the other hand, the polyaniline has the function of passivating an iron surface. Focusing on that function, application of polyaniline to an anticorrosive paint has also been studied. However, as described above, polyaniline is an insoluble polymer, and basically does not dissolve in a solvent except part of solvents (N-methyl-2-pyrrolidone, or the like). Then, such a method is mainly used that, when applied to an anticorrosive paint, a bulk of polymer is physically crushed to reduce a particle diameter and then mixed with paint. However, there is a limit to reduce a particle diameter by physically crushing a bulk of polymer. Thus, stability of polyaniline decreases in the paint, and particles eventually precipitate to separate from the paint. Furthermore, dispersion of polyaniline is insufficient in the coating.
As described above, polyaniline is a material that has been difficult to be handled when used as a paint.